Hydraulic structural apparatus

ABSTRACT

An improved building system for structural uses which employs high strength tubular elements to reduce the size, weight and extent of the structure required. The present invention utilizes tubular structural members with hollow cores filled with suitable hydraulic fluid and arranged to translate and distribute a sizeable portion of otherwise axial and lateral loads into an axial pre-stress in the thin walled tubular members which are arranged as steel columns or acts also as vertical bars in composite concrete columns or as secondary support (tension) or cross brace members. The primary columns of the building are tubular hollow members which are placed in tension through circumferential stress by means of a hydraulic system. The secondary floor support members suspended from the primary column support one or more floors by hydraulic means. Pressure equilibrium of the fluid within the column is achieved between the tubular primary and secondary support elements of the building. Other structural elements such as cross-bracing, are coupled to the hydraulic system and are used to restrain the column end conditions of the slender tubular columns. The present invention provides an improved means for constructing pressurized columns by utilizing an energized column with circulating fluid under pressure. Means are also provided in the present invention for eliminating the problem of fluid leakage within the hydraulic support members. The building system of the present invention also provides means for improving cable rod and long span structures for low rise buildings absorbing lateral and vertical shocks and displacements at the base of the support columns of conventional and hydraulic structures due to earthquakes.

United States Patent 1 Meckler HYDRAULIC STRUCTURAL APPARATUS MiltonMeckler, 16348 Tupper, Sepulveda, Calif. 91343 221 Filed: Apr. 24, 197221 Appl. No.: 247,134

[76] lnventor:

[52] US. Cl 52/292, 52/1, 52/167 [51] Int. Cl E04b l/36, E04b 1/98, E04b9/00 [58] Field of Search 52/1, 292, 2, 167

[56] References Cited UNITED STATES PATENTS 3,538,653 11/1970 Meckler52/1 Primary Examiner.lohn E. Murtagh Attorney, Agent, or Firm-Spensley,l-lorn & Lubitz Mar. 12, 1974 pre-stress in the thin walled tubularmembers which are arranged as steel columns or acts also as verticalbars in composite concrete columns or as secondary support (tension) orcross brace members. The primary columns of the building are tubularhollow members which are placed in tension through circumferentialstress by means of a hydraulic system. The secondary floor supportmembers suspended from the primary column support one or more floors byhydraulic means. Pressure equilibrium of the fluid within the column isachieved between the tubular primary and secondary support elements ofthe building. Other structural elements such as cross-bracing, arecoupled to the hydraulic system and are used to restrain the column endconditions of the slender tubular columns. The present inventionprovides an improved means for constructing pressurized columns byutilizing an energized column with circulating fluid under pressure.Means are also provided in the present invention for eliminating theproblem of fluid leakage within the hydraulic support members. Thebuilding system of the present invention also provides means forimproving cable rod and long span structures for low rise buildingsabsorbing lateral and vertical shocks and displacements at the base ofthe support columns of conventional and hydraulic structures due toearthquakes.

3 Claims, 18 Drawing Figures PATENIEUHAR 12 m 3.796l017 SHEEI 1 OF 6PATENTED m 12 :974

, slvssloiv SHEEI 3 0F 6 HYDRAULIC STRUCTURAL APPARATUS BACKGROUND OFTHE INVENTION 1. Field of the Invention 4 The present invention isgenerallyrelated to the field of construction systems and, moreparticularly, to those construction systems utilizing hydraulic members.

2. Prior Art Conventional column and beam framing systems disclosed bythe prior art which utilize solid steel or concrete members result in asignificant loss of available material strength when compression forcesare considered. The result often is a total structure which occupiesmore volume and is heavier than necessary provided most of thecompressive force could be transferred into the wall of an equivalenttubular column, creating an axial pre-stress in the wall which acts in adirection opposite to the normally applied axial column force andoperates to relax all or a significant percentage of the axialcompressive stress.

A large number of uneconomical operations and waste of structuralmaterials results in building construction today due to the traditionaltreatment of structural members acting either in compression or tensiondepending upon the resolution of the interacting forces. For example,concrete, a traditional building material, is noted for compressivestress but under ten sion has limited value unless steel reinforcing isadded. Similarly, structural steel members have excellent values undertension, but particularly in column support, members have low values incompression such that care must be taken in the selection of slendernessratio and section modulus when columns are subjected to compressiveloading. The carrying capacity of a long steel or composite steel andconcretecolumn or secondary support member is not only affected bypossible buckling (stability problems) but also because of any increasein moment due to an increase in moment arm due to building drift. Acolumn with equal and opposite moments at the ends is bowed in a singlecurvature while a column with equal moments at the ends is bowed indouble curvature. Also, restrained columns in frames undergoing lateralloading are bent in double curvature. As stated, a conventional columnand beam framing system with either steel or concrete constructionmaterial results in some loss of available material strength when therespective compression or tension forces are imposed on the variousinterconnected members. The result is a total structure which occupiesmore volume and is heavier than would be required if the normalcompression forces could be neutralized by pressure forces operating inthe opposite direction axially, to neutralize their effect and permit agreater load carrying capability for a given structure.

The present invention substantially solves those problems leftunresolvedby the systems disclosed by the prior art. Fluid filled columns andcross-braces are placed on the exterior of the structure, arranged inshear walls or placed within the exterior skin, depending upon thedesired architectural effect. Structural strength is maximized in thevarious columns, floor supports, cross-brace members, etc., by means ofa multiplicity of tubular elements filled with fluid, e.g.', inhibitedglycol-water solution. The fluid operates to redistribute a highproportion of axial and lateral load among the various structuralmembers joined together,

while providing a natural pre-stress effect. This, in turn, premitshigher loading than current practice will allow in comparable solidmembers of the same length. Tubular elements are used to construct theprimary columns and the secondary floor supports which rest on floatingpistons and carry a grouping of several floors.

SUMMARY OF INVENTION The present invention is an improvement in ahydraulic core construction for structures as shown and described in US.Letters Pat. No. 3,538,653.

The present invention as well as the invention described in US. LettersPat. No. 3,538,653 also by Milton Meckler issued Nov. 10, 1970 describesa building system concept together with design principles and mechanismswherein the live and static loads of a building are utilized to providefluid under pressure which is then used within the system to pre-stress,strengthen and otherwise redistribute the load forces of the building toother forces of the structure for overall structural efficiency,stability and safety. By means of the present invention, fluid pressureis supplied at various points in the structural system and the flowvolume pressure and level of that fluid under pressure at any givenpoint in the structural frame is made to depend upon the time varyinglive and static loads upon the building as reacted by the varioushydraulic devices and tubular elements of the structure in accordancewith the present invention. The live forces are those generated by wind,seismic forces, equipment, occupants, furniture, and the like, whereasthe static forces are the architectural loadings upon the building. TheMeckler prior patent describes such a concept. The present inventionincludes mechanical improvements to such a system as well as newcombinations of elements which are useful in such an overallsystem. Inmost structural frames for buildings the weight of the columns and wallsis generally negligible compared to the weight of the floors. In

accordance with the over-all concept of the present invention as well asthe concept described in US. Pat. No. 3,538,653 the weight of the floorsis utilized to generate fluid under pressure by supporting the floorsfrom a closed volume of fluid whereby any increase in the floor loadingor deflection'of the lateral bracing system is transposed to additionalpressure or flow by mechanical means in the closed volume of fluid.

In accordance with the present invention, support columns arecompensated in accordance with the load which they are to bear byproviding tubular members within or as a part of those columns, whichtubular members are pre-stressed by being interconnected as fluidpassages to receive the differences in fluid pressure resulting from thestatic loadings and live loadings of the building. Thus, in accordancewith the present invention different pressures are maintained atdifferent joints by mechanical means at different points in the varioustransducer elements by means of an independent accumulator circuit orthe like, whereby a balance of, forces commensurate with the loadsimposed upon the building or its deflection is achieved. Upon reachingthe foundation through the columns of the building, the foundations andthe ground must react the net axial load comprising the cummulative liveand dead loads of the building less any axial pre-stress made to act inopposite directions in accordance with the present invention. Also inaccordance with the present invention means are provided at the foot ofthe column for allowing both lateral and vertical movements of the earthin response to seismic shocks without transposing such vertical orlateral movement of the columns. Thus, in an earthquake the foundationmay move through a considerable series of both vertical and lateralmovements without causing any movement or damage to the building. Thepresent invention also includes mechanical improvements to the pressuretranslators previously described in U. S. Pat. No. 3,538,653.

Cross and horizontal brace members of the system of the presentinvention assist in transposing and redistributing various horizontaland vertical forces acting upon the structure and all surfaces attachedto it. By suspending the floors from the basic structural frame throughclosed volumes of liquid the system is further pressurized whenadditional stiffening of the columns to reduce deflection is necessary.The pressure is equalized in a given column through the fluid system ofthe present invention.

In accordance with the present invention an improved foundation supportmeans is provided for the vertical support columns of the structurewhich allow lateral and vertical ground displacement in the event ofearthquakes, without displacement of the columns at their base. Thepresent invention maximizes the benefits of unitized design bytranslating an axially applied compressive load into circumferentialtensile stress, thereby providing a pre-stress which permits high axialloading.

Tubular members filled, under pressure with liquid, can resistconsiderably higher forces than conventional solid members. Theincreased capacity is due to the prestressing type effect of thepressurized tubular members, and also to the increased resistance tobuckling of the columns and other compression members. F urthermore, bycoupling the vertical load carrying members with the secondary andbracing tubular members, pressure equalization within the tubularnetwork has a tendency to assist in resisting lateral forces due to windand/or earthquake.

Construction in accordance with the present invention utilizes tubularsteel columns either as the primary vertical support members of thestructure as in the case of an all steel column or a large portion ofload in a composite column. Such columns are filled with liquid andsecondary support or brace members are joined to the primary-column bymeans which place the fluid within the column in compression to therebyplace the tubular column members in tension through circumferentialstress. The secondary support members, i.e., those members supportingthe floors of the building from the primary column members or thoseacting as diagonal or horizontal brace members as hereinafter described.are thus supported. by or subjected to the pressure of the fluid in thetubular members. This pressure force is reacted partially by placing theprimary column tubular sections in compression with the balance of forcereacting in the plane of tubular skin as circumferential stress with byPoisson Ratio results in an axial pre-stress due to foreshortening oftubular structure along its axis. The secondary members supporting thefloor can also be tubular members with fluid under pressure creating bythe weight of the floors and associated walls and other loads supportedby it such that the pressure in the secondary tubular elements(developed by weight of floors and walls, etc., permits a largecomponent of axial tension stress to shift to a circumferential mode,thereby increasing its ability to handle greater axial stress values dueto resolution of stress forces in skin of tubular elements of secondarysupport members. Similarly, liquid under pressure can be transmitted toand contained within bracing members which are thereby increased instrength and resistance to bowing to resist lateral forces betweencolumns, for example. In this way the forces acting upon the columnarsupports of the structure do not exert compressive and buckling forcesupon the columns comparable to conventional framing methods using solidmembers, for example, but do rather obtain a sizeable proportion oftheir support by the circumferential stress in the columnar tubularmembers by reason of the pressure upon the liquid contained in themanifolded individual tubular elements comprising the column. Thepresent invention provides means for connecting such secondary floorsupports and brace members to said liquid filled primary columns suchthat the above described circumferential stress loading is obtained. Theaction of the hydraulic pressure within tubular elements also acts toresist the bowing effects under all loading conditions and can beharnessed to resist frame deflections upon upper building floors due towind and earthquake forces.

In accordance with the present invention energized columns can beutilized as the structural columns in order to achieve a substantialsaving of weight and structural material. Thus, in accordance with oneembodiment of the present invention the structural columns are designedas thin-walled tubular columns containing circulating fluid of suchvelocity and direction under pressure to pressurize the energizedcolumns to a level which assures that the net axial stress in the tubewalls will not become compressive upon the application of load or can beutilized to improve the heat transfer performance over thermal siphonfire protection systems of the type known to the art since the system ofthe present invention permits forced convection fire protection.

.The present invention also provides additional structural improvementsover the prior art systems.

Thus, the present invention permits minimum use of structural memberspermitting larger clear span floor areas by taking advantage of highstrength tubular elements to reduce the size and extent of the structurerequired. The invention accomplishes this maximized structural strengthin all steel columns or in composite columns by utilizing tubularstructural members with hollow cores filled with suitable hydraulicfluid and arranged to translate and distribute a sizeable proportion ofotherwise normal tension and compression forces into circumferential andlongitudinal stresses in the thin walled tubular members which arearranged as steel columns or also act as vertical bars in compositeconcrete columns or as secondary support (tension) or cross bracemembers. y

When comparing the potential weight and cost savings of a longpressurized tube with a conventional short solid structural column (oftype normallyfound in multirise buildings), it can be shown thatpressurization leads to roughly one-third savings in the weight of thebuilding shell and a potential cost savings therefor of one-third.Furthermore, when using a glycol-water solution as the pressurizationmedium, the further advantage of fire protection by thermal siphon isgained.

A weight savings will always result provided that the ratio of thepressure level to the fluid density is always greater than the ratio ofuniaxial yield strength to the material density of the solid column and,the tensile strength of the material is approximately two times itscompressive strength (or greater).

In short, prestressed columns favor low values of structural index.Thus, longer column lengths become more economical than solid columnmembers which favor high structual indexes. For the case of thepressurized tube, the potential wieght savings can be shown to beappreciable. The weight of the pressurized column varies directly withthe applied load and the column length, but is surprisingly independentof the modulus of elasticity. For this reason, almost any gas tightmaterial can be used, although materials of higher modulus of elasticitymay provide more compact members.

The novel features which are believed to be characteristic of theinvention, both as to its organization and method of operation, togetherwith further objectives and advantages thereof will be better understoodfrom the following description considered in connection with theaccompanying drawing in which a presently preferred embodiment of theinvention is illustrated by way of example. It is to be expresslyunderstood, however, that the drawing is for the purpose of illustrationand description only, and is not intended as a definition of the limitsof the invention. In the drawings:

FIG. 1 is a plan view of a building in accordance with the presentinvention;

FIG. 2 is a view in perspective showing the core and exterior framing ofthe building of FIG. 1;

FIG. 3 is a partial view of a building frame shown partly in schematicillustrating a typical cross brace and floor arrangement in accordancewith the present invention;

FIG. 4 is a partially schematic view in perspective of a typical columncross brace connection;

FIG. 5 is a partial view showing a typical floor support connection;

FIG. 6 is a cross-sectional view of a single structural column includinga liquid translator section in accordance with the present invention inthe structure together with two floor support connections to the column;

FIG. 7 is a view in section of a presently preferred embodiment of theapparatus for translating hydraulic forces from the secondary members tocross bracing members within a structure;

FIG. 8 is a schematic hydraulic diagram of a system in accordance withthe present invention;

FIG. 9 is an illustrative view ofa column utilizing circulating fluidunder pressure generated in accordance with the present invention toprovide a steady flow of high velocity fluid to achieve a pre-stresslevel approaching the column load;

FIG. 10 is a detailed view of an embodiment of an accumulator utilizedin connection with the column support members as shown in FIGS. 16 and17;

FIG. 11 is a view in elevation of a composite building in accordancewith the present invention in which a combination of structural membersin accordance with the present invention are utilized with conventionalstructural elements;

FIG. 12 is a view in perspective of the composite construction of theprimary and secondary supports of the composite construction of F IG.11;

FIG. 13 is a schematic view of an alternative building construction inaccordance with the present invention;

FIG. 14 is a partially schematic view of the interior circular ringsupport member of the building illustrated in FIG. 13; 7

FIG. 15 is a sectional view of a tubular member such as used in thebuilding of FIG. 13 which is prestressed in accordance with the presentinvention;

FIG. 16 is a sectional view showing prestressing member of FIG. 15 as itis utilized to pressurize the compressions ring of the building of FIG.13;

FIG. 17 is a view in elevation of a column foundation in accordance withthe present invention for absorbing vertical and lateral displacement atthe base of the column of the type which are encountered duringearthquakes; and

FIG. 18 is a view of ring and cable connection of F 1G 14.

Various features of the present invention are applicable to all buildingstructures but the overall system concepts are most applicable tobuildings upon which floor loadings are imposed. Accordingly, thepresent invention will be described in connection with the various typesof buildings, it being understood, however, that the present inventionis equally applicable to structures such as bridges.

Referring now to the drawings there is shown in FIG. 1 for purposes ofillustration, a plan view of an illustrative building employing theconstruction of the present invention and in FIG. 2 there is shown aview in perspective of the building of FIG. 1. In FIG. 3 there is shownthree vertical columns and one cross-brace section typical ofconnections used throughout the building structure. In FIG. 3 the threevertical columns 20 are connected through hydraulic translators 22. InFIG. 4 a single translator with primary column supports, cross-bracingand secondary floor support members is shown to illustrate the hydraulicflow and forces through a typical cross-brace translator. In FIG. 3 twofloors 24 are illustrated as being supported by this typical bracingsection. The static and live forces of the structure result primarilyfrom the floor loadings with some additional forces generated by lateralloads such as wind forces on the building. Thus, under the loadingconditions shown in FIG. 4 the vertical primary column 20 is normally incompression throughout its length extending to the foundation supportsfor the building. The axial prestress induced by means of the presentinvention can, however, result in no stress in tension or compression.The secondary supports 23 have the floors 24 attached to them asdescribed hereinafter, and are thus always in tension. The cross-braces21 will be in tensionor compression dependent upon the direction andextent of lateral forces. In FIG. 4, crossbraces' 21a and 21c are shownin compression while 21b and 21d are in tension.

Referring to FIG. 2 in the illustrative building hydraulic jointsidentified as 22a furnish support for the floors only. Hydraulic jointsidentified as 22b support the floors when interconnected with joint 22dwhereas joints such as 220 support two floors and function as across-brace. The support furnished and interrelationship of the jointsis dependent upon the structure but various types of joints are shown inthe structure in FIG. 2. In the illustrative structure of FIG. 2 thejoints identified as A support four floors; joints B and D areinterconnected to support four floors; and joint C supports two floorswhile furnishing cross-bracing. Each of the joints 220 through 22dincludes a hydraulic translator shown as typical in FIG. 6. In thestructure as shown in FIGS. 1 and 2 a center core 25 of hydraulicconstruction in accordance with the present invention is also utilized.The hydraulic construction of the core frame is comparable to thatdescribed in connection with the skeletal or exterior frame and will notbe separately described in detail. By utilizingv such a coreconstruction the core and exterior frame are joined by prestressedfloors to increase interior volume and eliminate the need for additionalcolumns or other structural vertical members in the spaces between thecore and the exterior frame.

In FIG. 6 for purposes of illustration one floor is shown supported fromthe column which includes the translator 22. The floor is supported on atrapped volume of liquid to supply pressure to the system through thehydraulic translator. In FIGS. 1 through 6 the vertical columns willsupport the floor slabs of the building, one of which floor slabs isshown in FIG. 6 and identified as 24. The slabs are supported from thecolumns but without lateral loading to the columns as set out in detailhereinafter. Each of the vertically extending columns in theillustrative embodiment of the present invention as shown in FIG. 6 is apressurized column. An embodiment utilizing energized columns consistingof a plurality of individual tubular members is shown in FIG. 9.Energized columns are known to the art and briefly stated are ones inwhich a circulating fluid is utilized to prestress a column. Thus, topreclude local buckling the steady flow of fluid is used to achieve aprestress level equal to the load on the column. In the presentinvention, energized tubes known as the closed tube type are utilized,one of which is shown partially schematically in FIG. 9 and describedmore fully hereinafter. For purposes of describing the energized column,however, it can be seen by reference to FIG. 9 that the column containsa series of tubular members 28 spaced circumferentially within thecolumn. The fluid flow is divided such that fluid under pressure fromthe translator is pumped downwardly through one-half of the tubes andupwardly through the other half. In such energized columns the fluidvelocity is such as to produce an axial pre-force of the magnitude equalto the column load. In the unloaded condition both the horizontal andvertical members resist an axial force equal to one-half the columnforce while in the fluid circulating condition only the horizontal axialforce is exerted upon the column. By selection of the proper velocitywithin the tubular cross section the loading can be equalized. Theenergized column can be thought of as comprising n closed tube elementalcolumns, each supporting the axial load divided by n. Due to fluidmomentum of equal quantities of flow passing a given transverse sectionof column at any time, as the fluid velocity approaches infinity, forexample the fluid weight approaches zero, thus the weight of the columnand fluid together are less than that of a statically pressurized fluidfilled column. In addition, the forces on the fluid produce a radialoutward force (r). The circular column can be constructed with anyradius desired by selecting n and the wall thickness of the closedtubular elements. By increasing the radius r, greater bucklingresistance can be obtained. In summary, the centrifugal force developedby the moving fluid creates a tensile prestress in the walls of thetubular elements whose value can be increased by increasing fluidvelocity without increasing the weight of the system, thus permittinggreater structural advantages than columns without fluid flow.

As will become more apparent hereinafter, the tubular hydraulic columnsof the present invention forming either pressurized columns or energizedcolumns can be employed in many ways in combination with conventionalstructural columns. Such tubular members can be combined into all steelcolumns by being coupled within tubular structural columns or they canbe connected with structural shapes such as l-beams, H- beams and thelike. The tubular members forming the columns could also be combinedinto a composite column which is a concrete column or a tubular steelcolumn filled with cement or other material. For purposes ofillustration the tubular members are shown and described ascomponents'of a composite steel column, such columns being designatedgenerally by the reference numeral 20.

In highrise buildings and other structures to which the presentinvention is particularly applicable, the strength required in thevertical columns will vary de pending upon the height and loading of thebuilding. A

larger number of tubular support elements within, or forming the primarycolumns, will be utilized at the high loading portions of the column tothereby maintain the overall diameter of the column constant. That is,at the lower portion of the columns where the highest loads areencountered a larger number of tubular elements are employed to carry alarger proportion of the load while at the upper locations along thecolumn less tubular elements are employed due to the decreased loading.In accordance with the present invention, the columns are supported attheir base by means of the hydraulic foundation support shownparticularly in FIGS. 16 and 17 and described hereinafter. The fluidpressure throughout the system is substantially uniform under staticloads except for the relatively minor increase downwardly due to thestatic head of the fluid. When the pressure imbalance tends to occurwithin the system due to transient loading, such as lateral wind loads,increased live loads on the floor or earthquake loading, the entireoverall pressure of the system tends to increase and mechanicalredistribution of fluid results as will become more apparenthereinafter.

When desirable for structural reasons or economy the pressure withinvarious portions of the columns and transducers can be varied or staged.One means would be the introduction of multiple stacked circuits in accordance with the present invention or by variation of pressures throughareas utilized to generate the pressures. I

The system of the present invention is energized by being filled with aliquid such as a glycol-water solution containing emulsions of solubleoil which act as rust inhibitors. Suitable sealing at all relativelymoving surfaces is provided as will become more apparent hereinafter. I

Referring now to FIGS. 5 and 6, each floor slab 24 is supported at itsproper height in the building by the primary columns 20 through liquidunder pressure. In conventional construction the slabs are fixed to thecolumns by means of tied supporting members such as horizontallyextending beams connected to the vertically extending columns. Suchconnection places the column in compression and exerts a buckling loadupon the column. Either the compression or buckling load are the designcriteria for a column in accordance with normal building construction.By means of the present invention, however, as shown particularly inFIG. 6 the floor slabs are connected to the vertical column 20 by meansof the hydraulic pressure translator designated generally as 22. Bymeans of such hydraulic pressure translator the floor slabs aresupported by axial tension in the secondary support members 23 and byliquid pressure transmitted throughout the system. The verticallyextending fluid columns furnish a portion of the support strength of thesupport column 20. Thus, the load of the floor slab and that imposedfrom lateral thrusts upon the individual tubular members of the columnis partially translated into a compressive force upon the fluid withinthe primary columnar members and secondary columnar and horizontal ordiagonal bracing (in tension or compression) members such that theircircumferential loading in tension is increased.

Positioned above the upper manifold 50 is an upper header 60 connectedto the manifold by suitable bolted flanges or other mechanical couplingmeans 39. The liquid column elements 28 are connected to the header asin FIG. 6 for a pressurized column and as in FIG. 9 for an energizedcolumn. The liquid columns 28 are tubular elements which are connectedinto the header, preferably by quick connect and disconnect mechanismswhich include a check valve 29, as shown schematically in FIG. 16. It isthe purpose and function of the header assembly in general to conductfluid under pressure to that portion of the system at which it isrequired. Thus, in the embodiment shown a liquid-header passage 62 isprovided in the header in communication with each of the fluid columns28, the plurality of which is contained within the support column 33which may be concrete, steel or a combination of both. The liquid header60 is, in turn, in fluid communication by means of a liquid passage 63with the liquid outlet passage 53 through a system of two-way checkvalves to prevent any leakage as described more fully hereinafter.Similarly, a lower header 64 is connected at the lower end of the liquidtranslator by means of flanges 38. The construction of the lower headeris comparable to the upper header, in that a liquid header passage 65 isin fluid communication through liquid passage 66 with the liquid outletpassage from the hydraulic translator through a system of two-way checkvalves. The liquid columns 28 are again affixed into the header.Positioned between the liquid outlet passage 53 from the pressuretranslator and the header passage 63 is a twoway check valve assemblythrough which fluid is conducted from the liquid side 22 of the pistonto the header 62, and thus .to the fluid columns 28 or vice versa,depending upon the circumstances.

The passage 70 is defined by two liquid branches, the first branch beinga fill branch 73, with a fill valve 74 positioned therein; the secondpassage 71 has a neutral check valve 72 positioned therein. Thus, liquidis communicated from the liquid column 92 under pressure to the header50 and thus to the liquid columns 28 by opening the fluid valve 74;after the columns have been filled with liquid, the fill valve 74 isclosed, and a drop in pressure in the liquid columns will cause apressure drop which in turn closes the short stroke check valve 72. Aspring loaded plate 81 is placed in the header 50 to close the fluidpath 62 in the event of a pressure drop in either the fluid columns 28or the translator. For this purpose the plate 81 is in two spring loadedsections; the first section 81a is spring loaded normally away from thefluid passage 63 and is maintained in the open position by the pressureof the fluid from the fluid outlet passage 63. lf the pressure in theoutlet 63 drops the plate 81a closes the passage 63 to maintain thepressure in the tubular columns 28. Conversely if the pressure in thetubular columns fails, as by a rupture or the like the portion 81b ofthe plate is urged closed by the springs 82 and prevents further flow ofliquid to the columns 28.

By conducting the liquid under pressure induced by the loading on thefloor slab through the inlet passages 52 and 56 to opposite sides of thefree floating piston 41 a pressure balance above and below the piston inthe liquid spaces 42 and 43 is achieved. The pressure of that liquid isthen transmitted as previously described through the pressure outletopenings 63 and 66 into the tubular column elements 28 to therebypressurize each of those elements equally. Additional liquid underpressure is availale through the liquid outlet passages 103 and 104 forpressurizing those auxiliary structural members such as cross braces.The liquid columns 28 forming part of the support column 20 are thuspressurized and an increase in structural strength of the compositecolumn can be achieved.

If additional liquid is required within the system, due to an adverseloading condition or because of leakage, the pressure balance within theliquid translator will be disturbed and the piston 91 as shown in FIGS.6 and 7 will move toward its upper or lower extremity of travel. If itreaches either extremity an automatic switch is positioned on the topand bottom surface of the piston and is triggered when the pistontouches either of these travel extremities. When the switch is actuated,a builtin pump 89b is started and additional liquid is drawn to or fromthe common accumulator circuit to the respective chamber as shown,particularly for chamber 93, in FIG. 8.

In an alternative embodiment of the present invention, the floatingpiston 41 of the translator 22 can be omitted. One of the improvementsof this invention over U.S. Pat. No. 3,538,653 is the elimination of therolling diaphragm seals and the need to predetermine the direction ofbuilding movement to modulate the flows to the various interconnectedmembers. By revised circuiting of the present invention a hydraulicstructure which is adaptable to all force modes (combinations ofsecondary floor support, cross brace movements, etc.) is possible withthe use of directional valves and/or pumps.

Furthermore, the piston shown in the primary column can be eliminated ifdesired. The latter piston serves to minimize shock loading effectsresulting from pressure rise by a quick stop of the flow of any of itscircuits and/or quick pressure drop." Decompression shock can prove asdestructive as compression shock, particularly in large bore cylindersof the type illustrated. The design of the piston size, weight, andgeometry are determined by the magnitude of pressure differenceanticipated, its duration, the anticipated time span between the minimumand maximum pressure levels, and the area affected by the shock. Therings at either end act as cushions that provide positive, gradualdeceleration and are tapered to eliminate shock upon entrance of freefloating piston. It should be appreciated that an accumulator,discharging rapidly in response to building movements, often tends toamplify shock conditions by its inherent time lag.

Where shock conditions permit elimination of free floating pistons, asimplified, primary column design is utilized.

Referring now to FIG. 9 there is shown the embodiment of the primarycolumn when an energized column is utilized rather than a pressurizedcolumn as shown in FIG. 6 and previously described. Thus, referring toFIG. 9 the manifold section 50 and the header section are comparable to,or the same as, those previously de scribed. The header, however, in theenergized column embodiment has only two fluid outlets at each end shownas 82 and 83 in FIG. 9, whereas in the embodiment of FIG. 6 a fluidoutlet from the header is provided for each tubular fluid column. Asubmersible pump 86 is positioned in the fluid chamber to one side ofthe partition wall..The pump is so constructed and arranged within theliquid volume that it has a suction side at one side of the partitionwall and a liquid outlet at the other side of the partition wall. Thus,as shown in the figure, the pump is placed in one-half of the liquidchamber and pumps through a port into the other half of the liquidchamber. The tubular column elements 28 are then connected as shown inFIG. 9 to be in fluid communication with the upper liquid chamber 88 andthe lower liquid chamber 89. As shown in FIG. 9 the tubular elements 28are arranged within the steel column or within a combination of steeland concrete. As shown in FIG. 9 the pump 86A then draws liquid upwardlythrough the liquid columns 28A at one side of the primary support columnand discharges the liquid into the other half of the liquid reservoir 88such that it flows downwardly through the fluid columns 288 conversely,the liquid pump 86B has its suction side on the upwardly flowing columnssuch that a closed circuit of high velocity liquid under pressure ismaintained through the tubular columns 28. Although two pumps are shown,one is sufficient to maintain the fluid flow. By utilizing two pumps ifone fails circulation can be maintained by the single remaining pump,thus improving reliability.

As shown in FIGS. and 6, there is attached to the primary support columna bracket 90 for supporting the load of the floor slab 24 by means of atransducer assembly including a piston supported by a contained volumeof liquid and transmitting the loading on the floors as the source ofhydraulic pressure within the structure. A cylinder 93 containing aclosed volume of liquid is in turn affixed to the bracket 90 or to thecolumn by any suitable mechanical means and it is preferable that aplurality of brackets be affixed at the diametrically opposed points onthe column for concentricity of load. Between the cylinder and thetranslator assembly, the cylinder is connected by means of a liquidconduit 92 to the liquid inlets 52 and 56 of the hydraulic translator. Apiston 91 is positioned within the cylinder with a piston rod 95extending from the piston outwardly from the upper end of the cylinder93. The cylinder is sealed by suitable means which allow verticalmovement of the piston rod while preventing leakage of liquid from thecylinder. In the presently preferred embodiment a double metallic o-ringseal 96 is utilized. The cylinder is filled with liquid and the pressureconduit 92 is connected in communication with the portion of thecylinder above the piston. Thus, a load imposed on the cylinder housingis transmitted to the liquid above the piston to increase the pressurethereof and that liquid pressure is transmitted through the liquidconduit 92. A floor slab 24 is connected to the cylinder housing throughany suitable mechanical means, one example of which is shown in FIG. 5.The transducer assembly thus, for example, extends from the interface ata to the interface at 90b. In FIG. 5, an embodiment particularly adaptedto space frame construction is shown in which the slab 24 is attached toan angle iron 96 which is in turn connected to a bracket 97 mounted uponthe cylinder housing 93. In the embodiment illustrated in FIGS. 5, 6 and2 the floor slab 24 is supported by the piston rod which is in tension.The piston rod 95 is connected to piston 91 which is supported by thebody of liquid under pressure within the cylinder 93. The liquid withinthe cylinder 93 is thus placed under high pressure by the load of thefloor slab through the piston and this pressure is transmitted throughthe liquid conduit 92 to the liquid inlet ports 52 and 56 of thepressure translator 22. In the branches which lead from the liquidconduit 92 to the liquid inlet ports, i.e., branches 99 and 100 in FIG.6, there are positioned appropriate check valves 101 which allow flow ofliquid only in the direction into the pressure translator. There is alsopositioned in the branch lines orifice assemblies 102 which allow theinsertion of orifices of different openings to thereby vary the pressureof liquid into the particular pressure translator. That is as previouslydescribed, the system of the present invention is adaptable to anoverall liquid balanced construction of a building or other structure.In high-rise buildings of magnitude over six stories, for example, thepressure in support columns can be increased at the lower portions ofthe columns where the compressive force is greatest. This allows the useof less expensive tubular materials at the upper portions where lessstrength is required. At various discontinuities different circuits andtransducers generating different pressures can be utilized. In FIG. 7there is shown an alternative embodiment of the present inven tion inwhich the secondary supports from which the floor slabs 24 are hung arealso pressurized for increased strength. In the embodiment of FIG. 7 thepiston rod 95 extends downwardly from the piston 91 such that the.piston 91 rests upon the cushion of liquid under pressure in chamber93a. The liquid under pressure is not only transmitted to the columnelements 28 through the translator 22 by way of pressure conduit 92 butalso into columns 280 forming the secondary sup port from which thefloor slab 24 is suspended. Additional fluid pressurization or return ofinternal leakage can be returned by pump to the system through line 127to accumulator 128.

Not only can columnar or transducer pressurization be varied buthydraulic building or structure section can be combined withnon-hydraulic conventional building systems for esthetic or economicreasons.

Referring now to FIGS. 2, 3 and 4, there is shown a building constructedin accordance with the present invention which provides a liquid filledbracing system and in particular a type of construction utilizing theliquid supported floor suspension system. In the building shownschematically in FIG. 2 a core structure is formed utilizing theelements of the present invention and an exterior or outer frame is alsoformed using the hydraulic translators of the present invention as floorsupports as interconnecting elements between the floors and the supportcolumn and as cross-bracing elements. One such composite framing elementis shown particularly in FIG. 3.

Referring to FIG. 2, structural strength is maximized in the variouscolumns, floor supports, cross-brace members, etc., by means of amultiplicity of tubular elements filled with fluid, i.e., inhibitedglycol-water solution. The fluid operates to redistribute a highproportion of axial and lateral load among the various structuralmembers joined together, while providing a natural prestress effect.This, in turn, permits higher loading than current practice will allowin comparable solid members of the same length. Tubular elements areused to construct the primary columns and the secondary floor orcrossbrace supports which are maintained by floating pistons and carry agrouping of several floors as shown.

In FIG. 2 there is shown an idealized-square building with center coreand skeletal structural frame joined by means of a prestressed floor toeliminate interior columns. Fluid filled columns, cross-braces, etc., inactual practice may be placed on the exterior as shown, arranged inshear walls or placed within the exterior skin, depending upon thedesired architectural effect.

Diagonal bracing placed on the exterior frame creates vertical trussesand gives the building a high torsional stiffness, improved resistanceto earthquake, etc. Slender tension members hung from every point ofintersection of the diagonal bracing support the load of one or morefloors. The load then travels down to exterior (or interior) columnswith lateral and axial forces partially reacted by fluid. The tensionmember concept in addition to its participation in the over-all truss,affords an opportunity to eliminate aboutone-half the number of columnsthat might otherwise be required using traditional methods.

The present invention provides an improved means for the design of tallstructures that economically resist wind and earthquake forces.Earthquake forces which act upon the structure result from erraticvibratory motion of the ground upon which .the structure is supported.Additionally, however, on very tall structures such as those above fortystories in height the wind forces approach the order of magnitude ofseismic forces. The present invention has the capacity to absorb andredistribute such impact loads to dampen prevailing frequencies. Thus,in conjunction with the previously described construction of the presentinvention for specifically damping transient loads a damping bar isconnected between each floorslab 24 and the adjacent primary column witha joint on either end similar to 96, FIG. 6. A viscous energy absorberis provided in each damping rod. The energy absorber comprises a closedliquid filled cylinder affixed to one position of the damping rod and aperforated piston affixed to the other portion of the rod. The piston islongitudinally movable within the cylinder. The perforations .throughthe piston allow the piston to move within the fluid but in a dampedmanner. Thus the rod can be lengthened or shortened but the rate atwhich either occurs is governed by the number and size of theperforations through the piston through which the fluid must flow whenthe piston moves within the cylinder.

A building in accordance with the present invention if assumed to be alinear model could be expressed as: F l 'l- H H-[ HH-[ X where [M], [C],[K], and [S] represent respectively the mass, damping, stiffness andstability matrix and x},{lr' 5c}, and {F}, represent respectively theacceleration, velocity, displacement, and forcing function of thestructure. The forcing function can be thought of as the characteristicenergy input from earthquake or wind, etc. which sets the basicstructure in motion. By proper selection of the hydraulic factors thatestablish the damping and stiffness matrix, the acceleration 'x'} anddisplacement {x} of the ovfall structure can be critically damped forthe probable range of earthquake energy levels which principally occurin frequencies ranging from approximately 0.1 to 10 cycles per second,corresponding respectively to the natural periods of a short (one story)building to a tall story) building, etc.

The hydraulic building structure is soft (rather than stiff). However,the stiffness matrix [K] is relatively high by virtue of the separatedcoluminar frame, crossbracing, etc. Since the value of the dampingmatrix at any limit [C] can be increased upon excitation by the variousmechanisms previously described (since it can be shown that [C] [C1 [C]x the structure can be programmed to approach high values of criticaldamping for the predetermined natural frequency of the structure.

Pressurized fluid within the tubular structures illustrated, not onlyoperates to provide favorable damping characteristics as earlierdescribed, but also inertial forces, as described by the term [S] {x}.

The ratio of [k] {x [S] {x} represents the ratio between the criticalbuckling load and the axial load used to generate the stability matrix[S]. By means of careful selection of fluid axial prestress levels,maintained within the tubular elements, the natural frequency of thebasic structure can be favorably modified so that the resultantdisplacement of the structure {x can be minimized for a given level of{F l and the stability matrix [S] is significantly improved overcomparable solid membered structures.

Referring now to FIG. 8 in order to clarify the liquid flow through atypical portion of a building constructed in accordance with the presentinvention a flow diagram of the hydraulics of the system is shown. Thefloor actuated piston 91 is shown schematically and induces a pressureon the liquid contained in the chamber 93a of cylinder 93 as previouslydescribed which pressure is then transmitted through the pressureconduit 92 to the chambers above and below the floating piston 41 of thetranslator 22. The translator shown as 22 is one of thetype contained ina column which in turn transmits liquid under pressure to the tubularelements 28 contained within a support column. Typical cross-bracing orhorizontal actuators are shown as 220 and 22d in FIG. 8 consistentlywith their location in the structure as shown in FIG. 2. The directionof liquid or pressure flow in the diagram is shown by the arrows in thevarious conduits. Thus, the pressure in the system is induced by theslab 24 at the piston 91 the load initiating the variable orifices 102and 103 through the inlets ports of the pressure translator 22. Theorifices 102 and 103 are sized to admit the desired amount of pressureto the chambers above and below the floating piston 41 which pressure isdetermined by the location of the translator in the over-all system. Thepressure is then transmitted from the translator 22 into the tubularelements 28 again through suitable valving as at 70 to pressurize thetubular elements 28 which form part of the primary support column 33.The check valve shown as 29 are check valves which allow a fieldconnecteddisconnected construction for the primary column. Onecross-brace translator with a cross-brace 21a in compression and onetranslator with a cross-brace 21b in tension are shown for purposes ofillustration. An accumulator 89a with a filter 89c is also shown. Thus,it can be seen that the weight of the floor slab on piston 91 (alsoshown in FIG. 6) causes pressure in the liquid beneath the piston 91 tobe transmitted to the underside of the floating piston 41 in thetranslator 22. By means of the floating piston the pressure is equalizedon the upper side of the piston 41 and the resultant high pressure istransmitted to the column member 28 above and below the translator inthe primary support columns. Similarly since cross-brace member 21b isin tension high-pressure is generated at the underside of the piston 91bof that cross-brace transducer while in the cross-brace transducer 21bhigh pressure is generated at the upper side of the piston 91b sincethat member is in compression. The resultant high pressure istransmitted to the low pressure side of the respective piston, as wellas to the pressurized support members 21a and 21b of the cross-braces.By means of the hydraulic circuitry and transducer pumps all pressurizedsupport members are at balanced high pressure induced by the variousforce bearing members of the structure.

The coil conditions of the building site in areas prone to earthquakecan materially effect the degree of damage to a building structuresubjected to vertical, horizontal, torsional, and/or rockingoscillations. Of principal concern in lurching, soil amplification, andsoil interaction is the response of the structure through its footingsand foundation that can be traced to characteristic soil properties,i.e., density, damping shearing modulus, poissons ratio, geometry oflayers, etc., re-

sponding to incident surface, shear and/or P wave velocities, emanatingfrom the exciting mechanism. It has been shown that all modes ofvibration of a rigid circular footing, resting on an elastic medium, canbe represented by an equilibrium equation similar to a damped singledegree of freedom system, except for the fact that the equivalentdamping and spring factors are functions of the frequency of vibration.The reaction of a rigid structure on flexible soil differs substantiallyfrom a flexible structure on rigid soil. Although the magnitude of suchreactions can be estimated from analysis of core specimens and thatsubsequent analysis of soil mechanisms of the site, limitations ofduplicating soil conditions at various points in the subsurface soilstructure in the laboratory make accurate prediction of forces,developed by soil reaction on the base of the footing, somewhatquestionable. To avoid the uncertainties of response to a potentiallywide range of the translational modes of vibrations we-have developed anhydraulic footing, capable of physical isolation of foundationsresponding simultaneously to the six degrees of freedom possible for themotion of a rigid body, namely translation in the three coordinate axisand rotation about each of the axes, including coupled motion, exhibitedprincipally as rocking and sliding.

Isolation of structures and foundations from ground motions has beenattempted in the past, using trenches and sheet wall barriers that fullysurround the source of vibration. Yet, such methods are of limited valuewhen dealing with earthquake generated shear waves, impinging normallyto ground surfaces below foundations. The configuration shown acts as avibration transducer with inherent damping and energy absorbing featureswhich operate to minimize effects upon fluid filled or conventionalstructures placed as shown upon it.

Referring now to FIGS. 16 and 17 there is-shown a hydraulic foundationsupport in accordance with the present invention which allows bothvertical and lateral movement of the earth at the foundation for theprimary columns of the structure without vertical or lateraldisplacement of the column. Thus, the columns and the building or otherstructures are isolated from the adverse effects of earth movement dueto earthquakes. In the embodiment shown the primary column 10 terminatesin a piston which includes an accumulator 121, sh0wn particularly inFIG. 10, to allow the flow of liquid to and from the accumulatordepending upon the exterior pressure of the liquid which is containedwithin a chamber defined between the piston and an open ended cylinder123. Thus, as shown in FIGS. 17 and 10, a quantity of liquid 124 isentrapped beneath the lower surface 125 of the piston upon which theprimary column rests. Suitable pressure filled metallic o-rings orequivalent seals are contained within the inner wall of the cylinder insealing contact with the outer surface of the piston such that theliquid within the cylinder 123 is entrapped and furnished with thevertical support for the piston 120 and thus for the primary column 10.If earth movements or other severe shocks cause a relative forceupwardly upon the foundation the cylinder 123 tries to move up along thepiston 120 and thus places the liquid into greater pressure at whichtime the valves 126 in the accumulator 121 open and allow the liquid toflow into the accumulator in order that the cylinder can move upwardlyrelative to the column without a resulting movement of the column.Similarly the primary column is laterally moveable relative to thefoundation. In the embodiment shown a series of radially extendingplates 127 are affixed to the primary column 10 and are contained withina fluid filled annulus 128 which forms a portion of the foundationsupport. Suitable means are provided for capturing the fluid within theannulus as by pressure filled o-rings shown in FIG. 17. The foundationannulus has a series of inwardly extended radial plates 129 whichoverlap in radius the column plates as shown in FIG. 16. The radialplates affixed to both the column and to the foundation are perforated.Thus, if the column tries to move laterally, it is damped by disapationof energy resulting from the fluid flowing through the openings in thevarious plates via tortuous path, etc., and the foundation can movewithout causing a similar movement of the column. An accumulator such asshown in FIG. 10 can also be used by being mounted I in combination withthe primary supports of the structures described to allow compensationfor sudden compression or decompression shocks in the hydraulic system.

One of the principal features of the subject invention is the dynamicseals, located in the various components, which in addition tocontaining pressure, are designed to withstand relative motion withoutdragging, wearing, galling, or welding, when subjected to ground motionor wind excitation. Such seals are well known in the art and comprisemetallic o-ring, labyrinth, metal lip, and two stage seals orcombinations of the above, as appropriate.

In the case of the secondary floor support and crossbrace seals thatoperate to house a shaft which must pass into, or out of, an area ofpressurized fluid, the axial mechanical seal is composed of materialsthat lap each other in a very fine fit, providing a very small axiallaminar path. By control of the quality of fit at these critical systempoints the flow is reduced to a level at which the fluid surface tensioncan complete the seal and there is no leakage. Wear is reduced bybalancing of the pressure induced sealing forces.

For seals joining the various internal members, a drain at, or between,seals can connect to a system return line (not shown) which can bereturned to the nearest adjacent accumulator by means of a single actingor reciprocating intensifier (not shown) that boosts the low pressureleakage oil to higher pressure by adding input horsepower to the circuitby taking advantage of the principle of ratio of areas. For example, asingle acting intensifier has two different cylinder bores with matchingpistons mounted on a common shaft. Low pressure internal drainage(return fluid) flows to the large cylinder end and acts on the largepiston area.

.The resulting force is transmitted by the smaller piston to the fluidin the smaller chamber, thereby providing sufficient pressuremultiplication to overcome the accumulator level setting in the sameratio as the piston area, etc. Volumetric pump output is intermittentand determined by the smaller piston diameter and stroke which iscarefully matched to overcome design leakage rates of internal seals,etc.

Referring now to FIGS. 11 and 12, there is shown a specific buildingstructure also in accordance with the present invention in which all ofthe floors of the structure are hung from overhead support members 140without the necessity of interior columns. The overhead members aresupported by vertical columns 141 and all of the load bearing structure142 is hung from the overhead support 140 by means of a piston supportedby a volume of liquid, as previously described, such that the load istransposed to pressure in the liquid within cylinders 143. The pressureof the liquid is then transmitted to conduits 144 only one of which isshown to thereby pressurize and increase the strength of the supportmembers 140. The column 141 can be conventional construction or can beof hydraulic construction 'the roof and bearing member loads beingtransmitted to the piston 132 to allow transmission of liquid pressurethrough the conduit opening 134 and through apertures 135 to therebyprestress the skin 130. This prestressing by load induced pressure isapplicable to many other structures such as catenarys for bridges andthe like.

I claim:

1. A structure comprising:

support columns extending upwardly from column foundations;

a piston at the lower end of each of said support columns;

load bearing members connected to and supported by said support columns;said column foundations comprising means at the lower end of said pistonsupporting said column on a volume of liquid;

means in combination with said piston to allow passage of liquid pastsaid piston if said column support is displaced vertically;

means laterally supporting said column in said body of liquid; and

means in combination with said lateral support means to allow passage ofliquid if said lateral support is displaced horizontally.

2. The apparatus as defined in claim 1 in which said piston supportincludes a pressure loaded accumulator;

said piston being supported within a cylinder upon a body of liquid; and

said accumulator being so constructed and arranged as to allow passageof liquid into and from said cylinder if said cylinder is verticallydisplaced.

3. The apparatus as defined in claim 2 wherein said lateral supportincludes a series of circumferentially spaced vanes affixed to saidcolumn;

said vanes being positioned within a closed liquid filled annulus; saidvanes including means to allow movement of said vanes within saidannulus if said foundation is laterally displaced.

UNITED STATES PATENT 0mm: CERTIFICATE OF CORRECTION Patent No. 3,796,017Dated ADIil 24, 1977 lnventor(s) MeckleI It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

In the Drawings:

Figure 4, the reference numeral "2le" should read IZlc Figure 6, thereference numeral "96" should be deleted. Figure 8, the referencenumeral "89 should read 89c Figure 8, the reference numeral "93" shouldread 93a Column 3, line 59, "with" should read" which line 64,"creating" should read created Column 5, line 11, "wieght" should readweight Column 9, line 32, "FIG. 16" should read FIG. 8

' Column 10, line 24, "availale" should read available Column 14, line 6the order of the symbols should be {3E 5c x Column 15, line 27 thereference numeral "21b" should read 21a line 28, the reference numeral"91b" should read 91a line 37, "coil" should read soil Signed and sealedthis 5th day of November 1974.

(SEAL) Attest:

McCOY GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents FORM Po-wso (10 65 uscoMM-oc eoa1o-po9 U.5. GOVERNMENT PRINTINGOFFICE: 869- 93 o

1. A structure comprising: support columns extending upwardly fromcolumn foundations; a piston at the lower end of each of said supportcolumns; load bearing members connected to and supported by said supportcolumns; said column foundations comprising means at the lower end ofsaid piston supporting said column on a volume of liquid; means incombination with said piston to allow passage of liquid past said pistonif said column support is displaced vertically; means laterallysupporting said column in said body of liquid; and means in combinationwith said lateral support means to allow passage of liquid if saidlateral support is displaced horizontally.
 2. The apparatus as definedin claim 1 in which said piston support includes a pressure loadedaccumulator; said piston being supported within a cylinder upon a bodyof liquid; and said accumulator being so constructed and arranged as toallow passage of liquid into and from said cylinder if said cylinder isvertically displaced.
 3. The apparatus as defined in claim 2 whereinsaid lateral support includes a series of circumferentially spaced vanesaffixed to said column; said vanes being positioned within a closedliquid filled annulus; said vanes including means to allow movement ofsaid vanes within said annulus if said foundation is laterallydisplaced.